Finnøy
Gearbox & Propeller
Finnøy Gear
Reduction gearboxes
•Cast steel gearbox housing
•Input shaft arranged for flexible coupling
•Hydraulic operated multi- plate clutch for secure and soft engagement
•Gearwheels with hardened and ground helical teeth for silent operating
•Hydraulic built-in servo unit for secure propeller pitch setting
•Output shaft with flange arrangement for propeller shaft coupling
•All bearings of roller type with low friction losses and long lifetime
•Spherical roller thrust bearing with low friction losses and long lifetime
•All parts are made of the most suitable material qualities
Single stage reduction gearboxes with horizontal or vertical offset
GXU gearboxes
Twin input – single output gearboxes
Twin input – single output gearboxes are often used when variable power to the propeller is required. The gearbox can be operated with one or two engines at the same time. In vessel were extra reliability is required this is a good solution. The engines can either be placed in front of or behind the gearbox. PTO’s for hydraulic pumps or shaft generator can also be delivered.
The twin input- single output gearbox gives a flexible solution. By using the correct combination of main engines and e-motors, the fuel consumption and emissions are reduced. The system gives flexibility, redundancy and safety. The gearboxes can be powered by diesel engines, liquefied natural gas (LNG) engines, e-motors or a combination of this.
2- speed gearbox
•Two different propeller speeds at a constant engine speed
•The propeller can be operated at optimal speed both at high and low load
•Minimized zero pitch loss at “low gear”
•Minimized propeller noise at “low gear”
•Fuel saving at low load
In high gear, clutch 1 is engaged and clutch 2 is disengaged, meaning full engine power can be given to the propeller, and excess power to the shaft generator. In low gear, clutch 1 is disengaged and clutch 2 is engaged, resulting in reduced engine power to the propeller due to lower propeller speed, and excess power to the shaft generator. Both gears allow for uninterrupted work of the generator at a constant speed of Power Take- off shaft. Additionally, the gearbox can be constructed with a 3rd clutch for disengaging the shaft generator when needed.
In addition to the two- speed gearbox, the vessel can also utilize floating frequency, allowing the engine speed to be lowered in “generator mode”. Variations in the engine speed which correspond to the floating frequency of the shaft generator from 50 Hz to 60 Hz allows for optimal propeller speed in the full operating range.
Hybrid propulsion
A hybrid propulsion system is suitable for ships with variable power requirements, enabling the engines and propellers to run optimally over a wide power range. The e-motor can be with a synchronous speed, but in order to have optimal propeller speed it is preferable to control the speed with a frequency converter for fuel savings and lower emissions.
The hybrid propulsion system combines the best from two systems; diesel, electric and diesel mechanical propulsion. Diesel mechanical drive is used for transit from A to B. For standby, DP or other operations modes with a benefit of variable propeller speeds diesel electrical drive is applied.
“Boost” drive means that the main engine and electric motor is operating together, for maximum power, which most often is used for heavy loads like towing, anchor handling or trawling. Applying an electrical motor in case of main engine breakdown is known as a “Take me home” drive. Ranging from basic to more complex configurations, a large number of operational modes are available.
Alt. 1 Diesel Electric Mode
Alt. 2 Diesel Electric Mode and Boost Mode
Alt. 3 Diesel Electric Mode, Generator Mode and Boost Mode
Twin input – single output gearboxes
PTO/PTI connected prior to the main clutch (C1 – C2). With separate clutches (C3) and (C4) on the main engine. This feature is also used on twin screwed vessels, giving the possibility to operate the vessel with only one main engine running.
Electric propulsion
•Optimum propeller speed over the whole operating range
•Minimized zero pitch loss
•Fuel saving at low load
Finnøy Propeller
CP propeller
The CP Propellers have a range from 1000 mm – 6000 mm in diameter. They can be delivered with 3, 4 or 5 blades. The propeller hub and blades are made in Ni.Al. -Bronze and can also be delivered in stainless steel. The pitch is adjusted by a pull- push rod inside the hollow propeller shaft. It transfers the axial force from the servo piston mounted inside the gearbox.
Propeller design
3 - bladed propeller
4 - bladed propeller
5 - bladed propeller
Benefits of controllable pitch propellers compared to fixed propellers:
•Secure and precise manoeuvrability
•An increase in the average speed
•Stern tube wear is reduced
•A constant speed at engine is possible
•Easy replacement of spare blades
•Engine wear is minimized
•Reduced fuel costs
•Dynamic position of vessel possible
•Stepless speed control of the ship
•Load control of engine is possible
•Full power available under all conditions
•The propeller can be designed for free running and towing
Nozzle
For vessels that require maximum towing thrust, a nozzle could be fitted. The nozzle increases the bollard pull by approx. 30-40% compared to an open propeller absorbing the same power. It can be delivered as a fixed nozzle or rudder nozzle.
The fixed nozzle- NaCa 19A profile
This is the “standard” nozzle that gives high nozzle thrust in towing condition and is a excellent choice for trawlers, tug boats, AHTS etc.
The fixed nozzle -Finnøy high speed profile
This nozzle is designed to give the same nozzle thrust as 19A type at low speed. However this nozzle is designed to reduce drag at a higher speed.
Rudder Nozzle